June 2018 Update

Task/Parse-an-IP-Address/Julia/parse-an-ip-address.julia

@@ -0,0 +1,34 @@
+const testdata = ["127.0.0.1", "127.0.0.1:80", "::1", "[::1]:80",
+                  "2605:2700:0:3::4713:93e3", "[2605:2700:0:3::4713:93e3]:80",
+                  "::ffff:192.168.173.22", "[::ffff:192.168.173.22]:80",
+                  "1::", "[1::]:80", "::", "[::]:80"]
+
+maybev4(ip) = search(ip, '.') > 0 && length(matchall(r":", ip)) < 2
+maybev6(ip) = length(matchall(r":", ip)) > 1
+
+function parseip(ip)
+    if (mat = match(r"^\[([:.\da-fA-F]+)\]:(\d+)$", ip))!= nothing ||
+       (mat = match(r"^([\d.]+)[:/](\d+)$", ip)) != nothing
+        port = mat.captures[2]
+        ip = mat.captures[1]
+    else
+        port = "none"
+    end
+    if maybev4(ip)
+        println("Processing ip v4 $ip")
+        iphex = hex(Int(Base.IPv4(ip)))
+        addresspace = "IPv4"
+    elseif maybev6(ip)
+        println("Processing ip v6 $ip")
+        iphex = hex(UInt128(Base.IPv6(ip)))
+        addresspace = "IPv6"
+    else
+        throw("Bad IP address argument $ip")
+    end
+    iphex, addresspace, port
+end
+
+for ip in testdata
+    hx, add, por = parseip(ip)
+    println("For input $ip, IP in hex is $hx, address space $add, port $por.")
+end